:root{
  --paper:#f7f6fc; --card:#ffffff; --ink:#16143a; --muted:#6b6987; --line:#e8e5f5;
  --teal:#5b4ff0; --teal-2:#4c40e6; --teal-soft:#eeebff; --amber:#19c2a0; --amber-soft:#dcf7ef;
  --red:#d64545; --red-soft:#fde7e7; --green:#0f9f83; --green-soft:#dcf7ef;
  --radius:16px; --shadow:0 1px 2px rgba(22,20,58,.04),0 10px 30px rgba(91,79,240,.07);
  --serif:"Noto Sans TC",-apple-system,"PingFang TC","Microsoft JhengHei",sans-serif; --sans:"Noto Sans TC",-apple-system,"PingFang TC","Microsoft JhengHei",sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0}
body{background:var(--paper);color:var(--ink);font:15px/1.7 var(--sans);min-height:100vh;display:flex;flex-direction:column}
a{color:var(--teal);}
h1,h2,h3{font-family:var(--sans);font-weight:900;line-height:1.35;margin:0 0 .6em}
h1{font-size:26px} h2{font-size:20px} h3{font-size:17px}
p{margin:0 0 1em}
small,.muted{color:var(--muted)}
code{background:#efedfb;padding:1px 6px;border-radius:5px;font-size:13px}

/* top bar */
.topbar{display:flex;align-items:center;gap:16px;padding:10px 24px;background:rgba(255,255,255,.92);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:15px;color:var(--ink);text-decoration:none;white-space:nowrap}
.brand img{height:34px;width:auto}
.brand small{font-weight:700;letter-spacing:.08em;padding-left:10px;border-left:1.5px solid var(--line);font-size:14px}
.brand-mark{width:32px;height:32px;border-radius:50%;background:var(--teal);color:#fff;display:grid;place-items:center;font-size:16px}
.nav{display:flex;align-items:center;gap:4px;margin-left:auto;flex-wrap:wrap}
.nav a{padding:6px 10px;border-radius:10px;text-decoration:none;color:var(--ink);font-size:14px}
.nav a:hover{background:var(--teal-soft)}
.nav a.on{background:var(--teal);color:#fff}
.nav-points{font-size:13px;background:var(--amber-soft);color:#0c8a71;padding:4px 10px;border-radius:20px;margin-left:6px}
.nav-admin{color:var(--amber)!important}
.nav-out{color:var(--muted)!important}
.nav-toggle{display:none;margin-left:auto;background:none;border:1px solid var(--line);border-radius:8px;padding:4px 10px;font-size:18px}
@media (max-width:900px){
  .topbar{flex-wrap:wrap;padding:10px 16px}
  .nav-toggle{display:block}
  .nav:not(.nav-guest){display:none;width:100%;flex-direction:column;align-items:stretch}
  .nav-open .nav{display:flex}
  .nav-points{align-self:flex-start;margin:6px 0}
}

main.wrap{width:100%;max-width:1080px;margin:0 auto;padding:28px 16px 48px;flex:1}
main.narrow{width:100%;max-width:440px;margin:0 auto;padding:48px 16px;flex:1}
.foot{text-align:center;color:var(--muted);font-size:12px;padding:20px}

/* cards & grid */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);margin-bottom:18px}
.card h2:first-child,.card h3:first-child{margin-top:0}
.grid{display:grid;gap:16px}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
.g-side{grid-template-columns:minmax(0,3fr) minmax(0,1fr)}
@media (max-width:800px){.g2,.g3,.g4,.g-side{grid-template-columns:1fr}}
.stat{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px}
.stat b{display:block;font-size:28px;font-weight:900;color:var(--teal)}
.stat span{color:var(--muted);font-size:13px}
.page-title{display:flex;align-items:flex-end;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-bottom:18px}
.page-title h1{margin:0}
.page-title p{margin:4px 0 0;color:var(--muted)}

/* forms */
label{display:block;font-weight:500;margin:14px 0 6px;font-size:14px}
label .hint{font-weight:400;color:var(--muted);font-size:12px;margin-left:6px}
input[type=text],input[type=email],input[type=password],input[type=number],input[type=url],select,textarea{
  width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:9px;background:#fff;font:inherit;color:var(--ink)}
textarea{min-height:90px;resize:vertical}
input:focus,select:focus,textarea:focus{outline:2px solid var(--teal-soft);border-color:var(--teal-2)}
.check{display:flex;gap:8px;align-items:center;font-weight:400;margin:10px 0}
.check input{width:auto}
.radio-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.radio-cards label{margin:0;border:1px solid var(--line);border-radius:10px;padding:12px;cursor:pointer;font-weight:400;background:#fff}
.radio-cards input{margin-right:6px}
.radio-cards label:has(input:checked){border-color:var(--teal);background:var(--teal-soft)}
@media (max-width:600px){.radio-cards{grid-template-columns:1fr}}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;background:var(--teal);color:#fff;border:0;border-radius:12px;padding:10px 18px;box-shadow:0 6px 16px rgba(91,79,240,.22);font:inherit;font-weight:500;cursor:pointer;text-decoration:none}
.btn:hover{background:var(--teal-2)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn-sm{padding:6px 12px;font-size:13px}
.btn-ghost{background:transparent;color:var(--teal);border:1.5px solid var(--line);box-shadow:none}
.btn-ghost:hover{background:var(--teal-soft)}
.btn-amber{background:var(--amber)} .btn-amber:hover{background:#13a98b}
.btn-danger{background:transparent;color:var(--red);border:1.5px solid var(--red-soft);box-shadow:none}
.btn-danger:hover{background:var(--red-soft)}
.btn-block{width:100%}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.spacer{flex:1}

.flash{padding:12px 16px;border-radius:10px;margin-bottom:16px;font-size:14px}
.flash-ok{background:var(--green-soft);color:var(--green)}
.flash-err{background:var(--red-soft);color:var(--red)}
.flash-info{background:var(--amber-soft);color:#0c8a71}
.flash a{font-weight:700}

/* tables */
.table{width:100%;border-collapse:collapse;font-size:14px}
.table th,.table td{padding:10px 8px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
.table th{color:var(--muted);font-weight:500;font-size:13px}
.table-wrap{overflow-x:auto}
.tag{display:inline-block;font-size:12px;padding:1px 8px;border-radius:20px;background:var(--teal-soft);color:var(--teal)}
.tag-amber{background:var(--amber-soft);color:#0c8a71}
.tag-red{background:var(--red-soft);color:var(--red)}
.tag-gray{background:#efeef5;color:var(--muted)}

/* auth */
.auth-card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:30px;box-shadow:var(--shadow)}
.auth-card h1{text-align:center}
.auth-alt{text-align:center;margin-top:16px;font-size:14px;color:var(--muted)}

/* hero */
.hero{display:grid;grid-template-columns:1.2fr 1fr;gap:40px;align-items:center;padding:30px 0}
.hero h1{font-size:40px}
.hero .lead{font-size:17px;color:#544b44}
.hero-visual{background:linear-gradient(160deg,var(--teal) 0%,#163a37 100%);border-radius:20px;padding:28px;color:#fff;box-shadow:var(--shadow)}
.hero-visual .bubble{background:rgba(255,255,255,.12);border-radius:14px;padding:10px 14px;margin:10px 0;max-width:85%}
.hero-visual .bubble.me{margin-left:auto;background:var(--amber)}
.steps{counter-reset:s;display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin:30px 0}
.steps div{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px}
.steps div::before{counter-increment:s;content:counter(s);display:grid;place-items:center;width:28px;height:28px;border-radius:50%;background:var(--amber);color:#fff;font-weight:700;margin-bottom:8px}
@media (max-width:800px){.hero{grid-template-columns:1fr}.hero h1{font-size:30px}.steps{grid-template-columns:1fr 1fr}}

/* chat */
.chat{display:flex;flex-direction:column;background:var(--card);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);height:min(70vh,640px);overflow:hidden}
.chat-log{flex:1;overflow-y:auto;padding:20px;display:flex;flex-direction:column;gap:12px;background:linear-gradient(#ffffff,#faf9ff)}
.msg{max-width:78%;padding:10px 14px;border-radius:14px;white-space:pre-wrap;word-break:break-word;position:relative}
.msg.user{align-self:flex-end;background:var(--teal);color:#fff;border-bottom-right-radius:4px}
.msg.assistant{align-self:flex-start;background:#f0eefc;border-bottom-left-radius:4px}
.msg.sys{align-self:center;background:transparent;color:var(--muted);font-size:13px;text-align:center}
.msg.err{align-self:center;background:var(--red-soft);color:var(--red);font-size:13px}
.msg-meta{font-size:11px;color:var(--muted);margin-top:4px;display:flex;gap:10px;align-items:center}
.msg-meta button{background:none;border:0;color:var(--amber);cursor:pointer;font-size:12px;padding:0}
.msg video{display:block;max-width:100%;border-radius:10px;margin-top:8px}
.typing{display:inline-flex;gap:4px}
.typing i{width:6px;height:6px;border-radius:50%;background:var(--muted);animation:b 1s infinite}
.typing i:nth-child(2){animation-delay:.15s}.typing i:nth-child(3){animation-delay:.3s}
@keyframes b{0%,80%,100%{opacity:.25}40%{opacity:1}}
.chat-form{display:flex;gap:10px;padding:12px;border-top:1px solid var(--line);background:var(--card);align-items:flex-end}
.chat-form textarea{min-height:44px;max-height:160px;flex:1}
.chat-tools{display:flex;gap:12px;align-items:center;padding:0 14px 10px;font-size:13px;color:var(--muted);background:var(--card)}
.chat-tools label{margin:0;font-weight:400;display:flex;gap:6px;align-items:center}
.correct-box{margin-top:8px;display:flex;flex-direction:column;gap:6px}
.correct-box textarea{min-height:70px;font-size:14px}

/* public profile */
.pub-head{display:flex;gap:18px;align-items:center;margin-bottom:18px}
.avatar{width:84px;height:84px;border-radius:50%;object-fit:cover;background:linear-gradient(135deg,var(--teal),#7b6cf6);color:#fff;display:grid;place-items:center;font-weight:900;font-size:34px;flex:none;box-shadow:0 0 0 4px #fff,0 0 0 6px var(--teal-soft)}
.avatar-sm{width:40px;height:40px;font-size:17px}
.pub-head h1{margin:0}
.chips{display:flex;gap:8px;flex-wrap:wrap;margin:8px 0}
.chip{border:1px solid var(--line);background:#fff;border-radius:20px;padding:4px 12px;font-size:13px;cursor:pointer}
.chip:hover{border-color:var(--teal);color:var(--teal)}
.url-box{display:flex;gap:8px}
.url-box input{font-family:ui-monospace,monospace;font-size:13px}

.list-item{display:flex;gap:12px;align-items:center;padding:12px 0;border-bottom:1px solid var(--line)}
.list-item:last-child{border-bottom:0}
.mem{padding:14px 0;border-bottom:1px solid var(--line)}
.mem:last-child{border-bottom:0}
.mem-title{font-weight:500}
.mem-body{white-space:pre-wrap;color:#4a423c;font-size:14px;margin-top:4px}
.tabs{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:16px}
.tabs a{padding:6px 14px;border-radius:20px;border:1px solid var(--line);text-decoration:none;color:var(--ink);font-size:14px;background:#fff}
.tabs a.on{background:var(--teal);color:#fff;border-color:var(--teal)}
.pkg{text-align:center}
.pkg b{display:block;font-weight:900;font-size:30px;color:var(--teal)}
.pkg .price{font-size:18px;margin:6px 0 12px}
pre.profile{white-space:pre-wrap;font-family:var(--sans);background:#fff;border:1px solid var(--line);border-radius:10px;padding:16px;max-height:520px;overflow:auto}

/* ---------- auth（登入、註冊等） ---------- */
body.auth{background:#fbf9fd}
.auth-shell{min-height:100vh;display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr)}
.auth-side{position:relative;overflow:hidden;background:linear-gradient(160deg,#f3f0ff 0%,#e9e4ff 55%,#dff6f0 100%);padding:40px 48px;display:flex;flex-direction:column}
.auth-side .brand img{height:40px}
.auth-side h2{font-size:clamp(28px,3vw,40px);line-height:1.3;margin:40px 0 10px}
.auth-side h2 .ul{position:relative;display:inline-block}
.auth-side h2 .ul::after{content:"";position:absolute;left:0;right:6%;bottom:-.06em;height:.13em;border-radius:99px;background:linear-gradient(90deg,#19c2a0,#36d6b6 60%,transparent);transform:rotate(-1.5deg)}
.auth-side p{color:var(--muted);max-width:420px}
.auth-side .art{margin-top:auto;border-radius:24px;overflow:hidden;box-shadow:0 30px 60px rgba(91,79,240,.18)}
.auth-side .art img{display:block;width:100%;height:auto}
.auth-main{display:flex;align-items:center;justify-content:center;padding:40px 20px;flex-direction:column}
.auth-main .auth-card{width:100%;max-width:420px;border:0;box-shadow:0 20px 60px rgba(22,20,58,.08);border-radius:22px;padding:34px}
.auth-main .auth-card h1{font-size:26px}
.auth-logo{display:none;justify-content:center;margin-bottom:18px}
.auth-logo img{height:38px}
.auth-back{margin-top:18px;font-size:13px;color:var(--muted)}
.auth-back a{color:var(--muted)}
@media (max-width:900px){.auth-shell{grid-template-columns:1fr}.auth-side{display:none}.auth-logo{display:flex}}

/* ---------- 對話：頭像、麥克風 ---------- */
.chat-head{display:flex;gap:12px;align-items:center;padding:12px 18px;border-bottom:1px solid var(--line);background:#fff}
.chat-head b{display:block;font-size:16px}
.chat-head small{color:var(--muted);font-size:12px}
.msg-row{display:flex;gap:10px;align-items:flex-end;align-self:flex-start;max-width:86%}
.msg-row .msg{max-width:100%}
.msg-av{width:34px;height:34px;border-radius:50%;object-fit:cover;flex:none;background:linear-gradient(135deg,var(--teal),#7b6cf6);color:#fff;display:grid;place-items:center;font-weight:900;font-size:14px}
.msg-av.lg{width:46px;height:46px;font-size:18px;box-shadow:0 0 0 3px var(--teal-soft)}
.mic{width:46px;height:46px;flex:none;border-radius:50%;border:1.5px solid var(--line);background:#fff;color:var(--teal);display:grid;place-items:center;cursor:pointer;transition:background .2s,color .2s}
.mic svg{width:22px;height:22px}
.mic:hover{background:var(--teal-soft)}
.mic:disabled{opacity:.35;cursor:not-allowed}
.mic.on{background:#e5484d;color:#fff;border-color:#e5484d;animation:micpulse 1.2s infinite}
@keyframes micpulse{0%{box-shadow:0 0 0 0 rgba(229,72,77,.5)}70%{box-shadow:0 0 0 12px rgba(229,72,77,0)}100%{box-shadow:0 0 0 0 rgba(229,72,77,0)}}
.voice-state{color:var(--teal);font-weight:500}
.chat-tools{flex-wrap:wrap;padding-top:8px}
@media (max-width:600px){.msg-row{max-width:94%}.chat{height:calc(100vh - 210px)}}

/* 對話背景 */
.chat-dark .msg.sys{color:#d9d6ff}
.chat-dark .msg.assistant{background:rgba(255,255,255,.94)}
.chat-dark .msg-meta{color:#8d89b5}
.bg-picks{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}
.bg-picks label{margin:0;cursor:pointer;font-weight:400;font-size:13px;text-align:center}
.bg-picks input{position:absolute;opacity:0;pointer-events:none}
.bg-picks .sw{display:block;height:58px;border-radius:12px;border:2px solid var(--line);margin-bottom:4px;background-size:cover;background-position:center}
.bg-picks input:checked + .sw{border-color:var(--teal);box-shadow:0 0 0 3px var(--teal-soft)}
@media (max-width:600px){.bg-picks{grid-template-columns:repeat(3,1fr)}}

[hidden]{display:none!important}

/* v6：AI 標示、浮水印、思念模式、每日題目 */
.ai-badge{display:inline-block;vertical-align:middle;font-size:11px;font-weight:700;line-height:1;padding:3px 7px;border-radius:20px;background:#efeef5;color:#5b5873;letter-spacing:.5px;margin-left:4px}
.chat-dark .ai-badge,.rt-top .ai-badge{background:rgba(255,255,255,.22);color:#fff}
.ai-watermark{position:absolute;right:12px;bottom:12px;z-index:5;font-size:12px;font-weight:700;color:rgba(255,255,255,.85);background:rgba(0,0,0,.28);padding:3px 9px;border-radius:12px;pointer-events:none;letter-spacing:.5px}
.vid-wm{position:relative;display:inline-block;max-width:100%}
.vid-wm video{display:block;max-width:100%}
.legacy-letter summary{cursor:pointer;font-weight:700}
.legacy-letter .letter{margin-top:12px;padding:16px 18px;background:repeating-linear-gradient(#fffdf8 0 31px,#efe7da 31px 32px);border-radius:12px;line-height:32px;white-space:normal}
.layers{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.layer{border:1px solid var(--line);border-radius:14px;padding:14px}
.layer b{display:block;margin-bottom:4px}
.layer .bar{height:6px;border-radius:6px;background:#efeef5;overflow:hidden;margin:8px 0}
.layer .bar i{display:block;height:100%;background:linear-gradient(90deg,var(--teal),#7b6cf6)}
.layer small{color:var(--muted);font-size:12px;display:block}
.dq{border:1px solid var(--line);border-radius:16px;padding:16px 18px;margin-bottom:12px;background:#fff}
.dq.done{opacity:.6}
.dq h3{margin:0 0 4px;font-size:16px;line-height:1.5}
.dq .meta{font-size:12px;color:var(--muted);margin-bottom:8px}
.dq textarea{min-height:90px}
.dq .row{margin-top:8px}
.dq .rec.on{background:var(--red);color:#fff}
.dq-progress{height:8px;border-radius:8px;background:#efeef5;overflow:hidden;margin:6px 0 16px}
.dq-progress i{display:block;height:100%;background:linear-gradient(90deg,var(--teal),#7b6cf6);transition:width .3s}
@media (max-width:760px){.layers{grid-template-columns:1fr 1fr}}

/* v7：測試邀請階段 */
.beta-note{margin:6px 0 14px;padding:12px 14px;border-radius:12px;background:var(--amber-soft);color:#0c6b58;font-size:14px;line-height:1.6}
.beta-note b{display:block;margin-bottom:2px;letter-spacing:1px}
.code-chip{font-family:ui-monospace,Menlo,Consolas,monospace;font-weight:700;letter-spacing:2px;font-size:15px}